1. Field of the Invention
The present invention relates generally to a multi-transmission/reception antenna system, known as a Multiple Input Multiple Output (MIMO) system. More particularly, the present invention relates to a transmission/reception apparatus and method for reducing the amount of feedback information transmitted from a plurality of receivers in a multi-user MIMO system, and a system thereof.
2. Description of the Related Art
Generally, the Beyond 3rd Generation (3G) system, that is, the 4th Generation (4G) system, refers to a system in which both a wireless network and core network provide characteristics of ubiquitous & seamless connection, high data rate, openness, and network convergence. The 4G system is designed to enable high-capacity data transmission, targeting the high data rate.
The 4G system should have a complex network configuration other than a single-network configuration. That is, the 4G system should have an integrated configuration of satellite network, wireless Local Area Network (LAN), Digital Audio Broadcast (DAB) network, Digital Video Broadcast (DVB) network, and the like. The integration of all types of networks enables multiple transceivers (for example, base stations and terminals) to simultaneously exchange data or signals using MIMO. This multi-user MIMO system arranges M antennas in a transmitter (or base station) and N antennas in receivers (or terminals). The transceivers can increase their data rate by exchanging signals using the antennas arranged in this manner.
To provide a multi-user MIMO service through the multiple antennas provided between transceivers, a transmitter needs Channel Quality Information (CQI) from multiple receivers. Therefore, the transmitter sends a request for feedback information including CQI, to the receivers. The transmitter requires more CQIs from the receivers in order to use multi-carrier technology and multi-antenna technology.
However, the increase in the amount of feedback information, or CQIs, increases not only throughput of the transceivers but also the required amount of resources, thereby causing a degradation of the entire system performance. In the conventional method proposed to address the drawbacks, the users having a CQI greater than a predetermined threshold are allowed to feed back their CQIs. Since the users having a better channel state perform CQI feedback, the method can reduce feedback overhead to some extent. However, because the users feed back CQIs without any processing, the method may still suffer from the feedback overhead.
Accordingly, there is a need for an improved transmission and reception apparatus and method for increasing system performance by reducing the amount of feedback information needed in a multi-user MIMO system.